1099-S how to file as a trustee

More information may help resolve your question.  For example, did the trustee sell the entire home and distribute 25% of the proceeds to the granddaughter?  Or did the trustee receive 25% of the proceeds for the sale of the house for the grandaughter?  Who received the 1099-S? Is the trustee filing a Form 1041 for the trust or estate?

Community user Critter has good advice about contacting a local professional to make sure you are on track.  It sounds like there is already an attorney familiar with your situation.

If the estate has already been settled, and the heirs have received their interest in the home, each of the heirs will report the sale of their interest in the home as the sale of an investment on their tax return for the year.  Each heir will report their share of the sales proceeds, and for the cost basis they will report their share of the fair market value of the home on the date of the grandmother's passing.

Here's how to enter the 1099-S for the sale of the home inherited from the grandmother:

1. Search for "1099b" and use the "Jump to 1099b" to enter the sale of your portion of the home.
2. Click "Add more sales" and answer "No" to the question about if you will receive a 1099-B.
3. Enter the name of the entity that sent you the 1099-S for the broker's name and continue to the next screen.
4. For the "What type of investment did you sell" dropdown, choose Other.
5. For the "How did you receive this investment" dropdown, choose "I inherited it". 
6. Enter the date the home was sold. 
7. The Proceeds is your portion of the 1099-S.
8. The cost basis is your share of the fair market value of the home on the date the grandmother passed. This can come from an appraisal, or if the sale was relatively close to the date of death, the sales price will approximate the fair market value on the date of death.

If there was a length of time between the passing and the distribution of the property, or if there was a trust involved, there may be the need for a Form 1041 Fiduciary tax return.  See this TurboTax article for more information about when a fiduciary return is needed and how to file one with TurboTax Business.